Overflow for liquid storage tanks



U 1H!) ,lilmll O. H. PILKEY OVERFLOW FOR LIQUID STORAGE TANKS Filed OG'.. 1l, 1946 Feb. 13, 1951 J/Q fl Patented Feb. 13, 1951 OVERFLOW FOR LIQUID STORAGE TANKS Orrin H. Pilkey, Chicago, Ill., assigner to Chicago Bridge & Iron Company, a corporation of Illinois Application October 11, 1946, Serial No. 702,806

Claims.

This invention relates to an overilow, and more particularly to an overiiow for a liquid storage tank.

Liquid storage tanks are generally provided with an overow outlet at the normal high-liquid level of the tank to limit the height of the liquid Within the tank. It has been customary in the past to provide such overilow outlets with a Weir box to increase the efciency of the outlet. Weir boxes generally are expensive to fabricate and their installation is not only diicult but is attended with the danger of ice forming in the liquid retained in the Weir box and the consequent stoppage of the overflow.

I have invented an am herein disclosing and claiming an overflow for a liquid storage tank which is inexpensive to manufacture and possesses no dimculty of installation and is not endangered by ice formation, and which also increases the capacity of the overiiow pipe by inhibiting the formation of a Vortex and thereby preventing air from being sucked into the overiiow and breaking the vacuum.

The invention will be described as embodied in the accompanying drawings, in which Fig. 1 is a side elevation of a liquid storage tank;

Fig. 2 is a vertical section along lines 2-2 of Fig. 1:

Fig. 3 is a horizontal section of the top of the outlet along lines 3 3 of Fig. 2; and

Fig. 4 is a View, partly in section, of the outlet viewed from the interior of the tank.

Referring more particularly to Fig. l, I show a spherical liquidV storage tank ill supported by a plurality of posts Il having vapor vents l2 in its top portion and an overflow pipe i3 extending from near the top of the tank down along its side. The overflow pipe I3 opens to the interior of the tank through an opening li and is normally positioned at the nominal high liquid level of the tank. Positioned above the opening is a substantially horizontal plate i5, the plate in the einbodi ment shown being generally semi-circular in shape, although some departure from semi-circular shape to accommodate the curvingA side walls of the tank is necessary as is shown in Fig. 3. The horizontal plate l5 is a vortex inhibiting member which, being positioned ,iust above the opening l, prevents the formation of vortices in the outlet and hence greatly increases the capacity of the overflow pipe. The plate i5 is conn nected to and may be supported by a vertical plate i6 attached to the side of the tank and bisecting the opening. This vertical plate I6 serves not only partially to support the horizontal plate i5 but also aids in preventing rotation of the liquid entering the outlet pipe. As can. be seen, no part of the overflow acts as a container for the liquid Within the tank, such as was common in the old style Weir boxes. Free circulation of the liquid adjacent the opening is therefore possible and the danger of the liquid freezing in the outlet in extreme temperatures is greatly lessened.

The shape of the horizontal plate i5 may, or' coursey be varied. I have found, however, that a shape beinfr substantially a section of a circle as shown is simple and eliicient. As an example, for a 3 overilovv pipe, that part of the horizontal plate adjacent the shell has a length of 15" and a width from the shell edge to the interior edge of 10". For a fi" overow pipe the length adjacent the shell is 18" and the width from the shell edge to the interior edge is l2". For a 6 overflow pipe the dimensions are 24" and 18 respectively. The vertical length of the vertical plate is relatively unimportant as long as it has suiiicient length to bisect the opening.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

l. In a liquid storage tank an overflow comprising: an overflow outlet on the side of the tank opening to the interior thereof at the nominal high liquid level, an outlet pipe on the exterior of the tank terminating ush with the side of the tank and connected to the overcw outlet and a substantially horizontal flat plate attached to the inside of the tank substantially tangent to the upper portion of the overilow outlet.

2. In a liquid storage tank having an outwardly convex sheet metal upper portion, an overflow comprising: an overflow outlet on the upper porf tion of the tank opening to the interior thereof,

an outlet pipe on the exterior of the tank terminating ush with the side of the tank and connected to the overflow outlet at the nominal high liquid level, a substantially horizontal plate ounted on the inside of the tank substantially tangent to the upper portion of the outlet, and a substantially vertical plate within the tank and longer than the diameter of the opening bisecting the outlet.

3. The overiiow of claim 2 in which the hori- 2,541,095 4 zontal plate is attached to the tank and is sub- REFERENCES CITED staritially semi-circular in shape. The followm i. g references are of record 1n the 4. The overoW of clalm 2 1n whlch the hollle of this patent:

zontal plate is substantially a, section of a circle having a radius of at least three times the di- 5 UNITED STATES PATENTS ameter of the outletopening. Number Name Date 5. The overflow of claim 2 in which the hori- 515,393 Brainard Mar. 6,1894 Y zontal plate is substantially semi-circular in 332,914 Law Oct, 9, 1906 shape and is Supported at least in part by the 1,188,267 Girsherski June 2o, 1916 Vertical plate. 10 1,493,843 Conrader May 13, 1924 ORRIN H- PILKEY 2,424,101 Lari July 15, 1947 

